NEW YORK (AP) — Of the four openly gay members of Congress, the two longest-serving stalwarts are vacating their seats. Instead of fretting, their activist admirers are excited about a record number of gays vying to win seats in the next Congress — and to make history in the process.

When the oaths of office are taken in January, Congress could have its first openly gay Asian-American, Mark Takano of California; its first openly bisexual member, Kyrsten Sinema of Arizona; and its first openly gay senator, Tammy Baldwin of Wisconsin.

In all, eight openly gay candidates are running as major-party nominees for the House of Representatives, the most ever, including the two incumbents who are favored in their races — Democrats Jared Polis of Colorado and David Cicilline of Rhode Island. There’s one gay Republican in the group, Richard Tisei, who is waging a competitive campaign for a House seat from Massachusetts.

A common denominator in all the races: Neither the gay candidates nor their rivals are stressing sexual orientation, and the oft-heard refrain is, “It’s not an issue.” If anti-gay innuendo does surface from lower echelons of a campaign, there are swift disavowals — even conservative candidates these days think twice about being depicted as biased against gays and lesbians.

“People know that bigotry is bad politics,” said Democrat Sean Patrick Maloney, a former adviser to President Bill Clinton who is trying to oust one-term Republican Rep. Nan Hayworth from New York’s 18th District in the Hudson Valley.

Mr. Maloney, who would be the first openly gay member of Congress from New York, has assailed Mrs. Hayworth for not supporting federal recognition of same-sex marriage, but he says voters are focused on economic and health care issues, not on gay rights.

“The voters in my district care more about why my opponent wants to end Medicare and defund Planned Parenthood than about who I love,” said Mr. Maloney, who is raising three children with his partner of 20 years.

The veterans departing from the House are Rep. Barney Frank, Massachusetts Democrat, perhaps the most powerful gay in elective office, who is retiring after 16 terms, and Ms. Baldwin, who is vacating her House seat after seven terms to run for the Senate. Recent polls show her running slightly ahead of her GOP opponent, former Wisconsin Gov. Tommy Thompson.

Mr. Thompson has not made an issue of Ms. Baldwin’s sexual orientation and said it was “a mistake” for his political director to have sent emails with a link to a video of Ms. Baldwin dancing at a 2010 gay pride festival.

Chuck Wolfe of the Gay and Lesbian Victory Fund, which recruits and supports gay political candidates, said Mr. Thompson’s response epitomized the changed atmosphere in which Republicans are less inclined to use sexual orientation as a wedge issue and anti-gay attacks are becoming taboo.

“We still have them happen in local races, but in the federal races we hope we’ll get through them without seeing these kind of attacks,” Mr. Wolfe said.

Ms. Baldwin’s decision to run for the Senate prompted another openly gay Democrat, state Rep. Mark Pocan, to enter the race to fill her seat from the 2nd District, which is based in Madison, the liberal home to the University of Wisconsin. Mr. Pocan won a four-way Democratic primary in August and is a heavy favorite to win on Nov. 6.

In Arizona, Ms. Sinema and Republican Vernon Parker are squaring off in a newly reconfigured district in the Phoenix area that both parties view as winnable.

Ms. Sinema, 36, has been a staunch gay-rights advocate during eight years in the Legislature and is at ease acknowledging her bisexuality. But she responded sharply during her primary campaign after being told that her Democratic rival had suggested that a bisexual couldn’t win the general election.

“It’s true that I’m openly bisexual,” she told the Washington Blade. “I have been my entire adult life, and I’ve managed to win four elections, and, meanwhile, he’s lost two, so perhaps it was being straight that was the problem here.”

Like Ms. Sinema, Mark Takano is considered a strong candidate in a newly redrawn and competitive district — California’s 41st, which includes Riverside. The GOP nominee, John Tavaglione, hasn’t made an issue of Mr. Takano’s sexuality

Mr. Takano, a 51-year-old high school teacher, ran losing races for Congress in 1992 and again in 1994, when he was routed by a GOP rival who sent anti-Takano mailers in shades of pink after Mr. Takano’s sexual orientation became an issue.

“That became front-page news,” Mr. Takano said. “Today, it’s just an interesting part of my background as opposed to being a sensational story. … People look back at what happened 18 years ago and say, ‘I can’t believe we ever did those things.’”

In Massachusetts, Mr. Tisei, a longtime state legislator, is running a vigorous campaign to unseat Democratic Rep. John Tierney. The National Republican Congressional Committee has included Mr. Tisei in its “Young Gun” program highlighting promising candidates.

There have been openly gay Republicans in Congress before — but they came out after being elected. Mr. Tisei would be the first Republican to enter Congress as an openly gay candidate.

Mr. Tisei is at odds with Republican Party orthodoxy on key social issues. He supports the Massachusetts law legalizing same-sex marriage and favors abortion rights. But he depicts himself as a fiscal conservative and says the GOP’s stance on social issues will moderate faster if people like him work from inside.

“I’ve been very welcomed and encouraged by the national party leaders,” he said in a telephone interview earlier this year. “As for issues of equality, you’ll never have true equality until you have advocates on both sides of the aisle.”

• In Colorado, Mr. Polis is an overwhelmingly favorite to win re-election in the 2nd District, which includes his liberal hometown of Boulder. He and his partner are raising a young son, which makes Mr. Polis the only gay member of Congress who’s a parent.

• In Rhode Island, Mr. Cicilline, a former mayor of Providence, is seeking a second term in the House but faces a tough challenge from Republican Brendan Doherty, a former head of the state police. During the Democratic primary campaign, there were brief flare-ups over complaints that supporters of Mr. Cicilline’s rival, Anthony Gemma, were engaging in anti-gay innuendo.

• In Idaho, Democratic state Sen. Nicole Lefavour — the first openly gay legislator ever in her state — is running against incumbent Republican Rep. Michael K. Simpson in the 2nd District. Of all the openly gay congressional candidates this year, she probably faces the longest odds, given that Mr. Simpson won re-election in 2010 with 69 percent of the vote.

In New York, the race between Mr. Maloney and Mrs. Hayworth is distinctive in part because Mrs. Hayworth has an openly gay son and is one of only three Republicans in the congressional gay, lesbian, bisexual and transgender caucus.

Have political dynamics evolved so thoroughly that being openly gay might now be an asset in the race?

“I don’t know I’d go that far,” Mr. Maloney said. “But there is a real power in being yourself. When you’re not afraid, when you live your life with honesty and integrity, it makes you a better parent, a better colleague, a better friend and a better candidate.”